This InfoSheet is number: 1021
Summary: This InfoSheet discusses the 2000
(Y2K) Proposal for an
Alewife and Smallmouth Bass Management Plan
by the St. Croix Fisheries Steering Committee
PROPOSAL by the St. Croix Fisheries Steering Committee regarding the management of anadromous alewives and smallmouth bass in the lower St. Croix River
1) The State of Maine should amend the existing legislation regarding St. Croix alewives to support the management plan proposed by the St. Croix Fisheries Steering Committee (below).
2) Jurisdictional agencies should adopt a management plan to:
a) At Woodland dam: Re-establish full fish passage.
b) At Grand Falls dam: Allow a limited spawning escapement [upstream] of four adult alewives per acre for the watershed above Grand Falls and below West Grand and Spednic Lakes, which lakes will remain closed to alewives. (Acreage and escapement numbers to be confirmed by the Steering Committee)*.
c) Establish an alewife monitoring program at Milltown and Grand Falls dams, and develop a plan for alewife harvest should stock levels exceed escapement targets.
d) Establish a smallmouth bass monitoring program on key lakes (Woodland Flowage, Grand Falls Flowage and Big Lake).
This plan should be implemented for an initial 4-5 year period, then reviewed and revised as warranted.
3) The Steering Committee will establish a public advisory process this year to assist with this management plan development and delivery
NOTE: The St. Croix Fisheries Steering Committee is comprised of representatives of the following agencies:
1) Canada: Dept. Fisheries & Oceans
2) Maine: Atlantic Salmon Commission, Dept. Inland Fisheries & Wildlife, Dept. Marine Resources
3) New Brunswick: Dept. Natural Resources & Energy
4) United States: U.S. Fish & Wildlife Service
5) International (as secretariat): St. Croix International Waterway Commission
* At a meeting of the Steering Committee in July 2000, the available acreage was agreed as 23,089 acres which,
at 4 fish/acre would yield 92,356 alewives. However, the Committee agreed to set the alewife escapement limit at 90,000 fish for the initial 4-5 year period of the plan.
St. Croix Fisheries Steering Committee CONSENSUS
Anadromous Alewives and Freshwater Smallmouth Bass on the St. Croix System - Maine and New Brunswick: May 2000
In early 2000, fisheries agencies and interest groups contributed answers to a series of questions on the St. Croix's anadromous alewife and freshwater smallmouth bass populations, to assist in discussions on the future management of these species. This information was collated into a 35-page document by the St. Croix International Waterway Commission and was circulated to interested parties in April 2000.
The St. Croix Fisheries Steering Committee, comprised of representatives of all of the St. Croix's jurisdictional fisheries agencies, met on May 9, 2000 to review this information and prepare this consensus position.
Copies of this document and the April 2000 compendium are available from the St. Croix International Waterway Commission: Mail Canada: #5 Route 1 Dufferin, St. Stephen, NB E3L 2Y8 Mail USA: P. O. Box 610, Calais, ME 04619 Email: firstname.lastname@example.org
1. ALEWIFE BACKGROUND
1a. How far up the St. Croix did alewives migrate prior to the early dams?
We don't know. Historic records imply but do not provide conclusive evidence to confirm alewife migration above Grand Falls.
1b. What impact did the Union Dam (built without a fishway in 1825) have on alewife numbers?
All of the anadromous species (alewives, [Atlantic] salmon and shad) were virtually shut off from migrating up the river from 1825 to 1869, with significant declines in stocks.
1c. What upstream migration of alewives was there in 1900-1980, prior to the new Milltown fishway?
There was some passage at a reduced rate through the old Milltown fishway. Construction of initial fishways at Woodland and Grand Falls in the 1960s re-opened areas above these locations to anadromous fish.
1d. What is the alewife's life history and what are the factors affecting its numbers?
See the response provided by Flagg and Squiers in the April 2000 compendium.
1e. What are the current markets for alewives? What are market needs and values?
Lobster bait is the primary market on a regional basis; demand has been low but is now increasing due to a shortage of alternate species. In the early 1990s, St. Croix alewives were harvested for salt fish export. A lack of natural harvest locations and guaranteed numbers has affected interest in a commercial fishery.
1f. What obligations might there be for sustenance fisheries for native groups?
There is a responsibility to ensure access to the resource, if this is desired. There is at least one aboriginal group in New Brunswick that has shown interest in the St. Croix alewife population; the Passamaquoddies in Maine have not shown interest at this time.
1g. What benefits/detriments do alewives have to other species in and beyond the St. Croix system?
Alewives are a forage species for some inland and marine fish as well as avian and mammalian predators. They may also serve as a buffer species to predation on young salmon and other gamefish. They contribute to the ecology of rivers, lakes and the nearshore coastal environment. Anadromous alewives in some instances may have a negative effect on landlocked smelt populations and concurrent landlocked salmon growth, and possibly on smallmouth bass.
2. SMALLMOUTH BASS BACKGROUND
2a. When were smallmouth bass introduced into the St. Croix system?
Sometime in the late 1800s.
2b. How and by whom were they introduced?
It is believed that they obtained access to the lakes from a pond in Maine privately-owned and stocked by a bass angling enthusiast.
2c. What is the smallmouth bass's life history and what factors affect its numbers?
See the response provided by Jordan in the April 2000. Numbers are affected by environmental factors (notably water temperature and level fluctuations) in the first year, also food availability and predation.
2d. What are the current markets for smallmouth bass angling? What are market needs and values?
The St. Croix has some of the most utilized smallmouth bass lakes in Maine, accounting for over 7000 angler-days per year on Big Lake and Grand Falls Flowage alone. The smallmouth bass fishery is an important economic factor in eastern Maine. In terms of angler-days expended, Smallmouth bass tie with brook trout and landlocked salmon as the most popular fishery. In New Brunswick, smallmouth bass rank 2nd-3rd among all sportfish.
2e. What benefits/detriments do smallmouth bass have to other species in the St. Croix system?
Juvenile smallmouth bass provide forage for other fish and avian species. They help to hold in check other prolific freshwater species such as white and yellow perch, resulting in the potential for a slightly better growth rate of the surviving individuals. They have a negative impact on brook trout populations, and a negative effect on juvenile Atlantic salmon where the habitats overlap. Smallmouth bass predation on smelts may reduce the availability of that species for landlocked salmon forage.
3. VALUE OF SPORT FISH GUIDING INDUSTRY TO THE ST. CROIX AREA
3a. How many individuals are employed in sport fish guiding and sporting camp jobs on the St. Croix system?
Roughly 200 are directly employed.
3b. What is the conservatively-estimated value of sport fishing to the local economy, directly and indirectly?
The total annual angler use for all Maine lakes and ponds in the St. Croix watershed probably exceeds 75,000 angler-days, which is valued at $5.45 million annually for the St. Croix watershed. A New Brunswick estimate is not available.
3c. How much of this value relates to the availability of smallmouth bass fishing?
4. HISTORY & EFFECT OF THE 1980 MILLTOWN FISHWAY REPLACEMENT
4a. Was upstream alewife migration enhanced by the new fishway?
Yes, with an increase in returns from 169,000 to 2,625,000 alewives in six years (1981-1987).
4b. What impact did the new fishway have on alewife numbers going upstream into the full watershed?
The increases were also observed at the upstream fishways.
4c. What management plan was put in place for this new resource and how has it been delivered?
Between the mid-1980s and 1993, measures were taken by the St. Croix Fisheries Steering Committee to control increasing alewife numbers. A 1993-1997 operational management plan approved by Steering Committee included an annual spawning escapement limit of 400,000 alewives and other management measures.
5. IMPACT OF ALEWIVES ON SPEDNIC LAKE FRESHWATER FISHERIES
5a. When did alewives first enter Spednic Lake after the Milltown fishway replacement and when were concerns regarding impacts on bass first voiced? Alewives were observed in Spednic Lake in the early 1980s, with complaints and research beginning in 1983 and 1985, respectively. In 1987, research divers observed large schools of juvenile alewives.
5b&c. What is a concise history of the concerns raised by freshwater interests and the actions taken by management agencies to address this issue?
The primary concern was a decline in the recreational fishery for smallmouth bass, accompanied by declines in the numbers of young-of-the-year bass and also smelts. Four major actions were taken: water levels were managed to support bass spawning, the lake was closed to the taking of bass, alewives were excluded from the lake and bass were transplanted from other lakes.
5d. When was Spednic Lake blocked to alewives and how was this accomplished and monitored?
It was blocked in May 1987 by closing the Vanceboro fishway during the spawning run. Alewives were excluded from Spednic Lake beginning in 1988 through 1999, with the exception of 1991 when a late closure of the fishway allowed some fish to enter the lake. A few alewives were observed at Mud Lake Falls that year.
5e. Based on research, what is the observed effect of alewives on bass in Spednic Lake?
The decline in bass recruitment closely coincided with the introduction of anadromous alewives into the lake. A combination of impacts may have been at play, including the limited productivity of Spednic Lake, due in part to water level fluctuations, and the possible competition for food between juvenile alewives and bass. There are differing views as to whether potential limited predation on juvenile bass by remnant alewife spawners may have been a factor.
5f. Is this situation unique to Spednic Lake, and if so why and how?
One might expect that similar low productivity lakes with severe water level fluctuations and significant alewife populations might exhibit similar effects on freshwater fish populations.
5g. Fifteen years later, what is the status of the Spednic bass population and fishery?
The Spednic Lake smallmouth bass stock has gradually improved in overall fish numbers, size composition and juvenile abundance.
5h. How did management of the Spednic situation affect user-management relations, and what lessons are to be learned?
User-management relations suffered from this situation, with longterm effects. The lessons learned: improve communication among parties, improve monitoring to support effective management, improve collaboration on multi-species management, and increase the involvement of stakeholders.
6. RESTRICTION OF ALEWIVES BELOW GRAND FALLS FLOWAGE
6a. When were alewives blocked at Grand Falls and why?
Alewives were first blocked at Grand Falls in 1991 as part of an assessment program aimed at developing a long-term alewife management plan, with recognition that the potential alewife stock size could exceed current fishway capacity. In 1994, the blockage was continued to support smallmouth bass studies. In 1995, the State of Maine enacted emergency legislation to close both the Woodland and Grand Falls fishways to migrating alewives. This legislation was passed without consultation with Canadian and American fisheries agencies or input from the St. Croix Fisheries Steering Committee.
6b. How are alewives blocked at Grand Falls and how has this been assessed?
Alewives are blocked at Grand Falls by removing 3-5 fishway baffles both above and below a stoplog slot near the downstream end of the fishway and by installing stoplogs in the slot. The goal is a substantial vertical drop that alewives cannot negotiate due to the fact that they do not jump. During periodic visual observations by researchers, no alewives were observed passing this obstruction. However there is some concern that this blockage may not be 100% effective.
6c. What have been the effects of the blockage on alewife numbers in the St. Croix system?
The blockage of alewife passage by fishway closures has been a major contributor to the sharp decline in anadromous alewife returns. Numbers declined from 2,624,700 in 1987 to 25,300 in 1999.
6d. Does this blockage affect other migratory fish species and, if so, how?
The blockage also prevents upstream migration of blueback herring, a species similar to alewives. Upstream migration of juvenile American eels (elvers) may be partially interfered with, although some will ascend over the wet fishway walls. The passage of Atlantic salmon is not an issue at this time due to the low runs (all fish are currently taken for broodstock).
7. RESTRICTION OF ALEWIVES TO BELOW WOODLAND DAM
7a. What are the provisions of the state law enacting this restriction and when did they come into force?
The Maine law (12 M.R.S.A. ß6134) restricting alewives to below the Woodland dam was passed by the Maine Legislature in April 1995 and came into force immediately.
7b. How are alewives blocked at Woodland and how has this been assessed?
The Woodland fishway is modified during the period from approximately April 30 through early July to create a vertical drop impassable to alewives in the lower section of the fishway. Maine Dept. of Inland Fisheries & Wildlife biologists have assessed the efficacy of this blockage by visual observations at the site during the alewife run and by research gillnetting, trapnetting, electrofishing and angling in the lakes above.
7c. What have been the effects of the blockage on alewife numbers in the St. Croix system?
As expected, the effect of this blockage has been to substantially reduce alewife numbers in the watershed.
7d. Does this blockage affect other migratory fish species and, if so, how?
Same as the response to 6d.
8. BASS POPULATIONS ON GRAND FALLS FLOWAGE & WEST BRANCH, PRE-&-POST ALEWIFE BLOCKAGE
8a. What studies of bass numbers and growth rates were done prior to 1990, and what correlations are drawn to causal factors?
The Maine Department of Inland Fisheries & Wildlife collected baseline smallmouth bass data on two study waters, Grand Falls Flowage in 1989 and Big Lake in 1991. DIF&W also collected baseline smallmouth bass data on West Grand Lake in 1990, where alewives had been denied access since 1982, using this as a control lake. These studies provided growth data.
8b. What studies of bass numbers and growth rates were done after 1990, and what correlations are drawn to causal factors?
The Maine Department of Inland Fisheries & Wildlife conducted smallmouth bass studies on catchable-sized bass on Big Lake in 1991, 1993, 1995, 1997, 1999; Grand Falls Flowage in 1993, 1995, 1997, 1999; Woodland Flowage in 1990, 1994, 1997; and West Grand Lake in 1990, 1993, 1995, 1997, 1999.
In addition, late fall samples of age 0+ smallmouth bass have been obtained from West Grand Lake, Big Lake and Grand Falls Flowage annually from 1994-1999, and from Woodland Flowage in 1994, 1995, 1997, 1998, 1999.
Two important findings have emerged from these studies:
1. Bass numbers remain excellent at Big Lake and West Grand Lake, with more larger-sized bass than in the years prior to 1992. Bass numbers at the Grand Falls Flowage are similar to pre-1991 levels; spawning habitat is a limiting factor on the abundance of this population.
2. Bass condition, in terms of weight at length, has been higher at Big Lake and Grand Falls Flowage since 1993, despite (a) no juvenile alewives as forage, (b) a higher percentage of larger bass, and (c) stockpiling of more bass due to new slot limit regulations. Anglers have commented favorably on the heavier bass they are now catching.
As bass weights were heavier during some years without alewives than with them, the effect of alewives on bass growth is uncertain.
8c. What is the current assessed health of the smallmouth bass resource in this area, relative to the 1970's?
With the possible exception of the Grand Falls Flowage, which has had reduced numbers of bass larger than 2 pounds, the smallmouth bass resource is more numerous and composed of more large fish , according to research findings for the Woodland Flowage and Big Lake as well as for West Grand Lake and Wabassus Lake (the last two blocked to alewives since 1982). This improvement is probably due to a combination of factors, including:
a) willingness of more anglers to release a very high percentage of their catch
b) willingness of anglers to release larger bass
c) slot limit regulations that protect 12-16 inch long bass from harvest at Big Lake, Grand Falls Flowage and West Grand Lake.
9. OTHER INTERACTING NATURAL POPULATIONS IN THE ST. CROIX SYSTEM, PRE-&-POST ALEWIFE BLOCKAGE
9a. How do St. Croix numbers of other species that may interact with alewives (ex: other fish, birds, mammals) compare for this period?
There is some concern that numbers of avian predators may have been affected in the lower section of the river.
10. BASS/ALEWIFE INTERACTIONS IN OTHER MAINE LAKES
10a. How was the Lake George (ME) study conducted, what were its findings, and how is it relevant to the St. Croix?
A cooperative study was carried out on Lake George by the Maine Department of Inland Fisheries & Wildlife, the Department of Marine Resources and the Department of Environmental Protection from 1987 through 1994, to determine the impact of stocking alewives at a rate of 6 adult fish/acre on the freshwater ecosystem. The results from this study are: there was no significant difference in the growth rate of brown trout, white perch, smallmouth bass, or smelt (with the exception of young-of-the-year) with or without the presence of alewives. There was a significant increase in the growth rate of pickerel and young-of-the-year smelt when alewives were present in the lake. There did not appear to be any change in the abundance of smelts as evidenced by the number found in gamefish stomachs or in the trawl survey with or without the presence of alewives.
10b. What has been the result of recent interactions of bass and alewives in Third Machias Lake, Meddybemps Lake and other area lakes?
This is unknown.
10c. Why are anadromous alewives being introduced into some lakes elsewhere in the state? Who is advocating and who is doing this?
It is the goal of the Maine Department of Marine Resources (DMR) to restore anadromous fish species to their historical habitat in the State of Maine. This restoration is accomplished through cooperative efforts between the Department of Marine Resources, Inland Fisheries and Wildlife, the Atlantic Salmon Commission, the U.S. Fish & Wildlife Service, and the National Marine Fisheries Service. Waters stocked with anadromous fish species, including alewives, are, in most cases, those waters which historically supported these species. Fish passage requirements at hydroelectric dams and fish stocking efforts over the past 30 years have significantly enhanced anadromous fish stocks in Maine rivers. This is supported by a number of state laws and interstate and federal initiatives.
10d. What is the potential impact of VEN (viral erythrocytic necrosis) and what can be done to assess/prevent alewife carriers? The potential impact of VEN to freshwater fisheries is unknown however this is not one of the diseases considered to be of regulatory concern by the ME Dept. of Marine Resources or Dept. of Inland Fisheries & Wildlife. VEN is endemic to a wide number of marine and diadromous species, including eels and smelt.
11. BASS/ALEWIFE INTERACTIONS IN OTHER NEW BRUNSWICK LAKES
11a. What information is available on bass/alewife interactions elsewhere in New Brunswick and how is it relevant to the St. Croix?
A study on these species in the Saint John River is in progress.
12. BASS/ALEWIFE INTERACTIONS OUTSIDE THE REGION
12a. What relevant information is available on bass/alewife interactions outside Maine/NB?
No known studies.
13. ALEWIFE STOCK MANAGEMENT OPTIONS
13a. How much spawning area is there for alewives in the St. Croix River and how many alewives are these capable of producing?
Potential production of anadromous alewives in various parts of the St. Croix River basin is given in Table 2 of the St. Croix Fisheries Steering Committee's Five-year (1993-97) operational plan for the development and management of the diadromous fishes of the St. Croix River (May 1993):
Drainage Area (hectares)
[Potential] Adult Production Weight (kg) (Weight assumes a production rate of 225.kg/ha.)
[Potential] Adult Production Number (Number assumes adult weight of 0.26kg)
Milltown to Woodland [Fully open now? Limited to 400,000?]
45,865 [anticipatedly do return to the sea]
Woodland to Grand Falls [Proposal is to open Woodland Dam fishway fully]
411,058 [anticipatedly would return to the sea from this area alone]
Accessible area above Grand Falls [Proposal is to open GF fishway limiting escapement to 90,000 alewives/year]
9,505,385 [anticipatedly would return to the sea from this area alone]
Above Spednic Lake outlet [Proposal does not allow alewife escapement above Spednic-Vanceboro Dam]
9,028,558 [Potential, IF OPENED]
Above Grand Lake Stream outlet [Proposal does not allow alewife escapement above WGL-GLS Dam]
12,680,481 [Potential, IF OPENED]
13b. Is it possible to have a management agreement that will halt alewife escapement if resulting bass declines are suspected?
The St. Croix Fisheries Steering Committee is committed to finding a way to achieve more proactive and precautionary protection of the smallmouth bass resource in balance with a sustainable alewife resource. It recognizes that it needs to establish a clear process involving agencies and stakeholders and an ongoing monitoring program to provide information for management.
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